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Journal ArticleDOI: 10.1080/17415993.2020.1817456

DFT computational insights into structural, electronic and spectroscopic parameters of 2-(2-Hydrazineyl)thiazole derivatives: a concise theoretical and experimental approach

04 Mar 2021-Journal of Sulfur Chemistry (Informa UK Limited)-Vol. 42, Iss: 2, pp 131-148
Abstract: It has been uncovered that compounds containing thiazole moiety display noteworthy biological properties, which have attracted the attention of many researchers in chemical biology as well as in me...

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Topics: Thiazole (59%), Moiety (52%)
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10 results found


Journal ArticleDOI: 10.1016/J.JICS.2021.100051
Abstract: In an endeavor to develop antibacterial agents, a series of six 1,4-benzodioxan-6-yl substituted chalcone derivatives were synthesized by the base-catalyzed Claisen-Schmidt reaction of the 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)ethan-1-one with fluoro and chloro substituted aromatic aldehydes. The synthesized products were characterized by FT-IR, 1H NMR, and 13C NMR spectroscopic techniques. The density functional theory (DFT) calculations were performed using the B3LYP functional with the 6-31G(d,p) basis set for the optimization of molecular geometries and frequency calculations. The CAM-B3LYP functional with a 6-31G(d,p) basis set was used in time-dependent density functional theory (TD-DFT) calculations for the electronic absorption studies. Optimized geometries, frontier molecular orbitals, and global reactivity descriptors' specifications were computed and addressed. The simulated electronic absorption spectra were recorded in the gas phase and dichloromethane (DCM) solvent. The electronic configurations, oscillator strengths, and excited state energies were also discussed. The theoretical UV–Vis and IR vibrational analyses were equated with the experimental findings for the assignment of absorption bands. The synthesized chalcones were evaluated for in vitro antibacterial activities against two Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli and Proteus vulgaris). The DFT simulations were correlated with the antibacterial findings and it was discovered that they were highly helpful in the designing antibacterial agents and to establish the structure–activity relationship. Theoretical calculations are in good correlation with the in vitro antibacterial results.

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7 Citations


Open accessJournal ArticleDOI: 10.22036/PCR.2020.248964.1837
Abstract: The (3,5-diphenyl-4,5-dihydro-1H-pyrazol-1-yl)(phenyl)methanone (DPPPM) were synthesized by using rapid and recyclable reaction media polyethylene glycol-400 (PEG-400) and catalytic amount of acetic acid. This method gives remarkable advantages such as simple workup and a greener method by avoiding hazardous and toxic solvents. The computational calculations for title compound have been carried out by using DFT method with B3LYP hybrid functional and 6-311++G (d, p) basis set. The structural parameters like bond lengths, bond angle, and dihedral angles were obtained from the optimized molecular geometry and discussed. This structural analysis shows, the DPPPM molecule has non-planar structure and possess C1 point group symmetry. The infrared vibrational spectral bands assignments were made by correlating experimental findings with the computed data and results shows good agreement. The electronic spectral properties were explored using the time-dependent density functional theory (TD-DFT) in the gas phase and two different polarity solvents. This obtained theoretical UV-Visible absorption results are in acceptable concurrence with the UV-Visible absorption experimental results. The solvent effect on wavelength of absorption also been reported. The frontier molecular orbital, MESP and global chemical reactivity parameters for the title molecule in the gas phase were reported and discussed. Theses result shows molecule possesses good strength and stability.

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Topics: Molecular geometry (57%), Bond length (54%), Molecule (54%) ... read more

4 Citations


Open accessJournal ArticleDOI: 10.13005/MSRI/180110
Rohit S. Shinde1Institutions (1)
Abstract: Present investigation deals with the synthesis and density functional theory study (DFT) of a chalcone derivative; (E)-3-(4-chlorophenyl)-1-(4methoxyphenyl)prop-2-en-1-one (CPMPP). The synthesis of a CPMPP has been carried out by the reaction of 4-methoxyacetophenone and 4-chlorobenzalehyde in ethanol at 300C under ultrasound irradiation. The structure of a synthesized chalcone is affirmed on the basis of FT-IT, 1H NMR and 13C NMR. The geometry of a CPMPP is optimized by using the density functional theory method at the B3LYP/6-31G(d,p) basis set. The optimized geometrical parameters like bond length and bond angles have been computed. The absorption energies, oscillator strength, and electronic transitions have been derived at the TD-DFT method at the B3LYP/631G(d,p) level of theory for B3LYP/6-31G(d p) optimized geometries. The effect of polarity on the absorption energies is discussed by computing UV-visible results in dichloromethane (DCM). Since theoretically obtained wavenumbers are typically higher than experimental wavenumbers, computed wavenumbers were scaled with a scaling factor, and vibrational assignments were made by comparing experimental wavenumbers to scaled theoretical wavenumbers. Quantum chemical parameters have been determined and examined. Molecular electrostatic potential (MEP) surface plot analysis has been carried out at the same level of theory. Mulliken atomic charge study is also discussed in the present study. CONTACT Rohit S. Shinde chemistry.rss@gmail.com PG Department of Chemistry, Mahatma Gandhi Vidyamandir’s Arts, Science and Commerce College, Manmad, Taluka-Nandgaon, DistrictNashik, India-423104. (Affiliated to Savitribai Phule Pune University, Pune, maharashtra, India. © 2021 The Author(s). Published by Enviro Research Publishers. This is an Open Access article licensed under a Creative Commons license: Attribution 4.0 International (CC-BY). Doi: http://dx.doi.org/10.13005/msri/180110 Article History Received: 23 March 2021 Accepted: 13 April 2021

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1 Citations


Journal ArticleDOI: 10.1016/J.BIOORG.2021.105259
Abstract: In this study, we report the expeditious synthesis of ten new antifungal and antioxidant agents containing heterocyclic linked 7-arylidene indanone moiety. The solvent-free microwave technique, ample substrate scope, superfast synthesis, and very simple operation are noteworthy features of this protocol. Antifungal activities of the newly synthesized compounds were evaluated against four fungal strains namely Rhizophus oryzae, Mucor mucido, Aspergillus niger, and Candida albicans. Most of the compounds were shown strong inhibition of the investigated fungal agents. In vitro, antioxidant potential against DPPH and OH radicals affirmed that the synthesized compounds are good to excellent radicals scavenging agents. The cytotoxicity data of the synthesized compounds towards HL-60 cells uncovered that the synthesized compounds display very low to negligible cytotoxicity. The structural and quantum chemical parameters of the synthesized compounds were explored by employing density functional theory (DFT) at B3LYP functional using 6-311G(d,p) basis set. The compound 3a is discussed in detail for the theoretical and experimental correlation. Time-dependent density functional theory (TD-DFT) at CAM-B3LYP functional with 6-311G(d,p) basis set was used for the electronic absorption study in the gas phase and indichloromethane and benzene solvents. The UV–Visible absorption peaks and fundamental vibrational wavenumbers were computed and a good agreement between observed and theoretical results has been achieved. From the DFT and antifungal activity correlation, it has been found that the 7-heteroarylidene indanones with more stabilized LUMO energy levels display good antifungal potential.

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1 Citations


Open accessJournal ArticleDOI: 10.13005/MSRI/180210
Vinayak Ramdas Bagul1Institutions (1)
Abstract: Using the synthetic potential of recyclable zinc oxide(ZnO) nanoparticles (NPs), a proficient, elegant, and rapid one-pot synthesis of a variety of 3,4-dihydropyrimidine-2(1H)-one/thione derivatives from the1,3-dicarbonyl compound, urea/thiourea, and various aromatic aldehydes havebeen unveiled in the present research. TheZnONPs were synthesized by theco-precipitation method. The powder X-ray diffraction method was employed for the determination of thecrystallite size of the synthesized ZnONPs.The hexagonal phase was obtained in the XRD pattern of the synthesized ZnO NPs with anaverage crystallite size of 25 nm.The current synthetic strategy offers excellent yields, a short reaction time, favorable reaction conditions, easy transformation, non-chromatographic product purification, and catalyst recyclability. Furthermore, the catalyst could be retrieved and reused without losing any of its catalytic activity. As a result, this elegant protocol is an adequate method fordihydropyrimidinone/thione synthesis.

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Topics: Zinc (56%)

1 Citations


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64 results found


Journal ArticleDOI: 10.1016/S0031-8914(34)90011-2
Abstract: Zusammenfassung Die von Fock im Rahmen seiner Naherungsmethode zur Behandlung des quantenmechanischen Mehrelektronenproblems aufgestellten Gleichungen werden auf etwas allgemeinerer Grundlage diskutiert. Es wird angegeben, wie man in eindeutiger Weise den einzelnen Elektronen bestimmte Wellenfunktionen und Eigenwerte zuordnen kann. Diese Eigenfunktionen genugen einer Gleichung, die in einem etwas anderen Zusammenhang von Fock abgeleitet wurde. Die Eigenwerte sind bis auf kleinen Korrektionen den Ablosungsarbeiten der einzelnen Elektronen entgegengesetzt gleich. Das erreichte Ergebnis hat nur Bedeutung in denjenigen Fallen, wo der Ansatz einer einzigen Slaterschen Determinante fur die Wellenfunktion sinnvoll ist.

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5,080 Citations


Open accessJournal ArticleDOI: 10.1063/1.4704546
Kieron Burke1Institutions (1)
Abstract: Density functional theory (DFT) is an incredible success story. The low computational cost, combined with useful (but not yet chemical) accuracy, has made DFT a standard technique in most branches of chemistry and materials science. Electronic structure problems in a dazzling variety of fields are currently being tackled. However, DFT has many limitations in its present form: too many approximations, failures for strongly correlated systems, too slow for liquids, etc. This perspective reviews some recent progress and ongoing challenges.

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1,050 Citations


Journal ArticleDOI: 10.1002/AIC.10713
Jianzhong Wu1Institutions (1)
01 Mar 2006-Aiche Journal
Abstract: Understanding the microscopic structure and macroscopic properties of condensed matter from a molecular perspective is important for both traditional and modern chemical engineering. A cornerstone of such understanding is provided by statistical mechanics, which bridges the gap between molecular events and the structural and physiochemical properties of macro- and mesoscopic systems. With ever-increasing computer power, molecular simulations and ab initio quantum mechanics are promising to provide a nearly exact route to accomplishing the full potential of statistical mechanics. However, in light of their versatility for solving problems involving multiple length and timescales that are yet unreachable by direct simulations, phenomenological and semiempirical methods remain relevant for chemical engineering applications in the foreseeable future. Classical density functional theory offers a compromise: on the one hand, it is able to retain the theoretical rigor of statistical mechanics and, on the other hand, similar to a phenomenological method, it demands only modest computational cost for modeling the properties of uniform and inhomogeneous systems. Recent advances are summarized of classical density functional theory with emphasis on applications to quantitative modeling of the phase and interfacial behavior of condensed fluids and soft materials, including colloids, polymer solutions, nanocomposites, liquid crystals, and biological systems. Attention is also given to some potential applications of density functional theory to material fabrications and biomolecular engineering. © 2005 American Institute of Chemical Engineers AIChE J, 2006

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325 Citations


Journal ArticleDOI: 10.1016/J.NEUROPHARM.2004.09.007
Koki Kato1, Keisuke Hirai1, Keiji Nishiyama1, Osamu Uchikawa1  +5 moreInstitutions (1)
01 Feb 2005-Neuropharmacology
Abstract: Ramelteon (TAK-375) is a novel melatonin receptor agonist currently under investigation for the treatment of insomnia. This study describes the neurochemical and receptor binding characteristics of ramelteon in vitro. Ramelteon showed very high affinity for human MT1 (Mel1a) and MT2 (Mel1b) receptors (expressed in Chinese hamster ovary [CHO] cells), and chick forebrain melatonin receptors (consisting of Mel1a and Mel1c receptors) with Ki values of 14.0, 112, and 23.1 pM, respectively, making the affinities of ramelteon for these receptors 3-16 times higher than those of melatonin. The affinity of ramelteon for hamster brain MT3 binding sites was extremely weak (Ki: 2.65 microM) compared to melatonin's affinity for the MT3 binding site (Ki: 24.1 nM). In addition, ramelteon showed no measurable affinity for a large number of ligand binding sites (including benzodiazepine receptors, dopamine receptors, opiate receptors, ion channels, and transporters) and no effect on the activity of various enzymes. Ramelteon inhibited forskolin-stimulated cAMP production in the CHO cells that express the human MT1 or MT2 receptors. Taken together, these results indicate that ramelteon is a potent and highly selective agonist of MT1/MT2 melatonin receptors.

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Topics: Ramelteon (63%), Melatonin receptor agonist (63%), Agonist (56%) ... read more

307 Citations


Open access
Jianzhong Wu1Institutions (1)
01 Jan 2006-
Abstract: Understanding the microscopic structure and macroscopic properties of condensed matter from a molecular perspective is important for both traditional and modern chemical engineering. A cornerstone of such understanding is provided by statistical mechanics, which bridges the gap between molecular events and the structural and physiochemical properties of macro- and mesoscopic systems. With ever-increasing computer power, molecular simulations and ab initio quantum mechanics are promising to provide a nearly exact route to accomplishing the full potential of statistical mechanics. However, in light of their versatility for solving problems involving multiple length and timescales that are yet unreachable by direct simulations, phenomenological and semiempirical methods remain relevant for chemical engineering applications in the foreseeable future. Classical density functional theory offers a compromise: on the one hand, it is able to retain the theoretical rigor of statistical mechanics and, on the other hand, similar to a phenomenological method, it demands only modest computational cost for modeling the properties of uniform and inhomogeneous systems. Recent advances are summarized of classical density functional theory with emphasis on applications to quantitative modeling of the phase and interfacial behavior of condensed fluids and soft materials, including colloids, polymer solutions, nanocomposites, liquid crystals, and biological systems. Attention is also given to some potential applications of density functional theory to material fabrications and biomolecular engineering. © 2005 American Institute of Chemical Engineers AIChE J, 52: 1169 –1193, 2006

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274 Citations